MEPX
Chapter 7 of 10All chapters
  1. 1What makes a password strong
  2. 2The reuse problem
  3. 3Password managers
  4. 4Two factor authentication
  5. 5Passkeys
  6. 6Recovery and backup access
  7. 7Breaches
  8. 8Phishing your credentials
  9. 9Where secrets live
  10. 10A realistic plan

Chapter 7 of 10

Breaches

When a site loses your data.

What leaks

Ideally only salted hashes, which resist cracking for strong passwords. Often it is more: addresses, phone numbers, and answers to security questions.

  • Check your address against a reputable breach notification service.
  • Change the password on that site and anywhere you reused it.

After the notification

Look for changes you did not make: new recovery addresses, forwarding rules, connected apps and active sessions. Attackers install persistence, then wait.